1. Field of the Invention
This invention relates generally to bicycle seats and more specifically to a shock absorbing bicycle seat mounting post assembly.
2. Brief Description of the Prior Art
Numerous bicycle seats have been provided in the prior art that are adapted to include spring biased support structures carried on bicycles. For example, U.S. Pat. Nos. 3,466,086 to James et al; 4,182,508 to Kallai et al. 4,456,295 to Francu; 2,107,561 to Brandt et al.; 640,483 to McKenzie; 564,142 to Beardsley; 2,162,399 to Hayes; 4,736,983 to Furbee; and 4,997,232 to Johnsen (inventor of the present invention); as well as French Patent No. 870,860 and British Patent No. 560,679 are all illustrative of such prior art. While these units may be suitable for the particular purpose to which they address, they would not be as suitable for the purposes of the present invention as hereinafter described.
Brandt et al. '561 and Johnsen '232 are examples of spring supported seat structures which are exposed to dust and dirt accumulation and could be dangerous if the skin or the fingers of a person is pinched by the collapsing spring, and this would be especially important when small children are riding as a second passenger on the bicycle.
Moreover, none of the prior art arrangements appear to adequately account for the varying sizes of bicycle seat posts relative to that of the bicycle frame tube within which they mount. The Brandt et al. '561 patent shows a typical arrangement wherein the top portion of the frame tube is slit vertically, and a generally U-shape clamp has its legs clamped toward one another by means of nut-and-bolt combination. However, this type of clamping is inadequate when the diameter of the seat post is much smaller than the internal diameter of the frame tube. Furthermore, if the U-shape clamp is forced to attain its minimum diameter under such a condition, the top portion of the frame tube is deformed, permanently weakening the frame tube and making it difficult to insert a seat post of a larger diameter at a later date.
Finally, although Brandt et al., the British patent '679, Hayes '399, and others use a spring loaded seat post members sliding within a bicycle frame tube, there are no provisions for stabilizing the extreme ends of the moving parts of the seat posts, and further there are no means provided for cushioning the impactive forces imparted to the seat posts except for the reactive forces of the compression springs. It would be advantageous if bicycle seat posts which use compression springs would also have a supplementary impact absorbing feature. None of the known prior art provides this combination.